blob: f6877fc7705ae84823c9d91732e804a1b5d73f0f [file] [log] [blame]
// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package cache
import (
"bytes"
"context"
"fmt"
"go/scanner"
"go/token"
"go/types"
"regexp"
"strconv"
"strings"
"golang.org/x/tools/go/analysis"
"golang.org/x/tools/go/packages"
"golang.org/x/tools/internal/lsp/protocol"
"golang.org/x/tools/internal/lsp/source"
"golang.org/x/tools/internal/lsp/telemetry"
"golang.org/x/tools/internal/span"
"golang.org/x/tools/internal/telemetry/log"
errors "golang.org/x/xerrors"
)
func sourceError(ctx context.Context, fset *token.FileSet, pkg *pkg, e interface{}) (*source.Error, error) {
var (
spn span.Span
err error
msg, category string
kind source.ErrorKind
fixes []source.SuggestedFix
related []source.RelatedInformation
)
switch e := e.(type) {
case packages.Error:
kind = toSourceErrorKind(e.Kind)
var ok bool
msg, spn, ok = parseGoListImportCycleError(ctx, fset, e, pkg)
if ok {
break
}
if e.Pos == "" {
spn = parseGoListError(e.Msg)
} else {
spn = span.Parse(e.Pos)
}
// If the range can't be derived from the parseGoListError function, then we do not have a valid position.
if _, err := spanToRange(ctx, pkg, spn); err != nil && e.Pos == "" {
return &source.Error{
Message: msg,
Kind: kind,
}, nil
}
case *scanner.Error:
msg = e.Msg
kind = source.ParseError
spn, err = scannerErrorRange(ctx, fset, pkg, e.Pos)
if err != nil {
log.Error(ctx, "no span for scanner.Error pos", err, telemetry.Package.Of(pkg.ID()))
spn = span.Parse(e.Pos.String())
}
case scanner.ErrorList:
// The first parser error is likely the root cause of the problem.
if e.Len() <= 0 {
return nil, errors.Errorf("no errors in %v", e)
}
msg = e[0].Msg
kind = source.ParseError
spn, err = scannerErrorRange(ctx, fset, pkg, e[0].Pos)
if err != nil {
log.Error(ctx, "no span for scanner.Error pos", err, telemetry.Package.Of(pkg.ID()))
spn = span.Parse(e[0].Pos.String())
}
case types.Error:
msg = e.Msg
kind = source.TypeError
spn, err = typeErrorRange(ctx, fset, pkg, e.Pos)
if err != nil {
return nil, err
}
case *analysis.Diagnostic:
spn, err = span.NewRange(fset, e.Pos, e.End).Span()
if err != nil {
return nil, err
}
msg = e.Message
kind = source.Analysis
category = e.Category
fixes, err = suggestedFixes(ctx, fset, pkg, e)
if err != nil {
return nil, err
}
related, err = relatedInformation(ctx, fset, pkg, e)
if err != nil {
return nil, err
}
}
rng, err := spanToRange(ctx, pkg, spn)
if err != nil {
return nil, err
}
ph, err := pkg.File(spn.URI())
if err != nil {
return nil, fmt.Errorf("finding file for error %q: %v", msg, err)
}
return &source.Error{
File: ph.File().Identity(),
Range: rng,
Message: msg,
Kind: kind,
Category: category,
SuggestedFixes: fixes,
Related: related,
}, nil
}
func suggestedFixes(ctx context.Context, fset *token.FileSet, pkg *pkg, diag *analysis.Diagnostic) ([]source.SuggestedFix, error) {
var fixes []source.SuggestedFix
for _, fix := range diag.SuggestedFixes {
edits := make(map[span.URI][]protocol.TextEdit)
for _, e := range fix.TextEdits {
spn, err := span.NewRange(fset, e.Pos, e.End).Span()
if err != nil {
return nil, err
}
rng, err := spanToRange(ctx, pkg, spn)
if err != nil {
return nil, err
}
edits[spn.URI()] = append(edits[spn.URI()], protocol.TextEdit{
Range: rng,
NewText: string(e.NewText),
})
}
fixes = append(fixes, source.SuggestedFix{
Title: fix.Message,
Edits: edits,
})
}
return fixes, nil
}
func relatedInformation(ctx context.Context, fset *token.FileSet, pkg *pkg, diag *analysis.Diagnostic) ([]source.RelatedInformation, error) {
var out []source.RelatedInformation
for _, related := range diag.Related {
spn, err := span.NewRange(fset, related.Pos, related.End).Span()
if err != nil {
return nil, err
}
rng, err := spanToRange(ctx, pkg, spn)
if err != nil {
return nil, err
}
out = append(out, source.RelatedInformation{
URI: spn.URI(),
Range: rng,
Message: related.Message,
})
}
return out, nil
}
func toSourceErrorKind(kind packages.ErrorKind) source.ErrorKind {
switch kind {
case packages.ListError:
return source.ListError
case packages.ParseError:
return source.ParseError
case packages.TypeError:
return source.TypeError
default:
return source.UnknownError
}
}
func typeErrorRange(ctx context.Context, fset *token.FileSet, pkg *pkg, pos token.Pos) (span.Span, error) {
spn, err := span.NewRange(fset, pos, pos).Span()
if err != nil {
return span.Span{}, err
}
posn := fset.Position(pos)
ph, _, err := findFileInPackage(pkg, span.FileURI(posn.Filename))
if err != nil {
return spn, nil // ignore errors
}
_, m, _, err := ph.Cached()
if err != nil {
return spn, nil
}
s, err := spn.WithOffset(m.Converter)
if err != nil {
return spn, nil // ignore errors
}
data, _, err := ph.File().Read(ctx)
if err != nil {
return spn, nil // ignore errors
}
start := s.Start()
offset := start.Offset()
if offset < len(data) {
if width := bytes.IndexAny(data[offset:], " \n,():;[]"); width > 0 {
return span.New(spn.URI(), start, span.NewPoint(start.Line(), start.Column()+width, offset+width)), nil
}
}
return spn, nil
}
func scannerErrorRange(ctx context.Context, fset *token.FileSet, pkg *pkg, posn token.Position) (span.Span, error) {
ph, _, err := findFileInPackage(pkg, span.FileURI(posn.Filename))
if err != nil {
return span.Span{}, err
}
file, _, _, err := ph.Cached()
if err != nil {
return span.Span{}, err
}
tok := fset.File(file.Pos())
if tok == nil {
return span.Span{}, errors.Errorf("no token.File for %s", ph.File().Identity().URI)
}
pos := tok.Pos(posn.Offset)
return span.NewRange(fset, pos, pos).Span()
}
// spanToRange converts a span.Span to a protocol.Range,
// assuming that the span belongs to the package whose diagnostics are being computed.
func spanToRange(ctx context.Context, pkg *pkg, spn span.Span) (protocol.Range, error) {
ph, _, err := findFileInPackage(pkg, spn.URI())
if err != nil {
return protocol.Range{}, err
}
_, m, _, err := ph.Cached()
if err != nil {
return protocol.Range{}, err
}
return m.Range(spn)
}
// parseGoListError attempts to parse a standard `go list` error message
// by stripping off the trailing error message.
//
// It works only on errors whose message is prefixed by colon,
// followed by a space (": "). For example:
//
// attributes.go:13:1: expected 'package', found 'type'
//
func parseGoListError(input string) span.Span {
input = strings.TrimSpace(input)
msgIndex := strings.Index(input, ": ")
if msgIndex < 0 {
return span.Parse(input)
}
return span.Parse(input[:msgIndex])
}
func parseGoListImportCycleError(ctx context.Context, fset *token.FileSet, e packages.Error, pkg *pkg) (string, span.Span, bool) {
re := regexp.MustCompile(`(.*): import stack: \[(.+)\]`)
matches := re.FindStringSubmatch(strings.TrimSpace(e.Msg))
if len(matches) < 3 {
return e.Msg, span.Span{}, false
}
msg := matches[1]
importList := strings.Split(matches[2], " ")
// Since the error is relative to the current package. The import that is causing
// the import cycle error is the second one in the list.
if len(importList) < 2 {
return msg, span.Span{}, false
}
// Imports have quotation marks around them.
circImp := strconv.Quote(importList[1])
for _, ph := range pkg.compiledGoFiles {
fh, _, _, err := ph.Parse(ctx)
if err != nil {
continue
}
// Search file imports for the import that is causing the import cycle.
for _, imp := range fh.Imports {
if imp.Path.Value == circImp {
spn, err := span.NewRange(fset, imp.Pos(), imp.End()).Span()
if err != nil {
return msg, span.Span{}, false
}
return msg, spn, true
}
}
}
return msg, span.Span{}, false
}